1. Field of the Invention
The present invention relates to an inflatable airbag curtain assembly that prevents twisting of the inflatable curtain during production, installation, or service of the curtain. More particularly, the present invention relates to an inflatable airbag curtain assembly that includes a stiffening member extending from the gas guide to the nearest mounting location to prevent twisting of the inflatable curtain.
2. Description of Related Art
Inflatable safety restraint devices, or airbags, are well accepted for use in motor vehicles and have been credited with preventing numerous deaths and injuries. Inflatable airbags are now mandatory on most new vehicles. Airbags are typically installed as part of a system with an airbag module in the steering wheel on the driver's side of a car and in the dashboard on the passenger side of a car. In the event of an accident, a sensor within the vehicle measures abnormal deceleration and triggers the ignition of an explosive charge contained within an inflator. Expanding gases from the charge travel through conduits and fill the airbags, which immediately inflate in front of the driver and passenger to protect them from harmful impact with the interior of the car.
Side impact airbag systems have also been developed in response to the need for similar protection from lateral impacts between a passenger and the side of a vehicle's interior. This might occur when another vehicle collides with the side of the car, or in a rollover situation where the side of the car is repeatedly impacting the ground. These airbags, which are commonly referred to as “inflatable cushions” or “inflatable curtains,” may be mounted on or near the roof rail, or the portion of the frame that extends along a length of the vehicle between the side windows and the roof.
Recently, airbag technology has continued to advance such that inflatable airbags curtains are now enlisted to provide roll-over protection as well as side impact protection. During a roll-over accident, the vehicle occupants can be jostled considerably, thereby causing the occupant to impact various parts of the vehicle interior. Even worse, the occupant may be ejected from the vehicle. Alternatively, a head or limb of an occupant may extend outside the vehicle during the roll-over. Such “occupant excursion” during roll-over accidents is a common cause of automotive fatality, particularly in the case of vehicle occupants that are not wearing a seat belt during the roll-over.
Conventional curtain airbags attempt to combat the dangers of side impact or roll-over accidents by providing impact protection and occupant retention. The inflatable curtain is typically compacted, i.e., folded, rolled, or processed through a combination of folding and rolling, to stow the cushion behind a headliner covering the interior of the roof of the vehicle. The curtain may be designed to unroll or unfold downward from the roof of the vehicle and then inflate beside the person as a means of preventing the person from hitting the door, window, or lateral side of the vehicle. Since a vehicle occupant may be leaning forward, reclined in the seat, or at any position in between, such curtain airbags are usually designed to be long enough to cover the whole interior side of the vehicle, protecting occupants in both front and rear passenger compartments.
Generally, the inflatable curtain airbag must be sized to hold large volumes of inflation gas and to descend below the window sill. Consequently, when not inflated the airbag curtain includes a significant amount of material. This material is then rolled, folded, or otherwise gathered to form a tight, tubular bundle. A wrapper (sometimes called a “sock”) that fits around the curtain is then added to ensure that the airbag curtain is kept rolled or folded.
The stored curtain is then mounted either on or proximate a roof rail of the vehicle. Such mounting is generally accomplished via a two-step process. First, the curtain must be held in the proper position. This can be done by either having multiple workers hold the airbag or by attaching the airbag to sophisticated jigs, hooks, clips, or mounting brackets (collectively “brackets”) that have been placed into slots in the body of the vehicle. Once the airbag curtain has been secured in the proper location, the workers are free to affix the airbag curtain assembly to the vehicle using fasteners such as bolts, screws, rivets, and the like. Usually these fasteners are threaded into one or more attachment tabs that have been added along the top of the airbag curtain to facilitate the assembly and mounting process. A metal gas guide that extends from the inflator is then connected to an inlet port of the inflatable curtain.
Although inflatable airbag curtain systems have significantly increased the overall safety of the vehicle, problems and challenges still exist that limit the ability of airbag and vehicle manufacturers to implement and use inflatable curtains on all types of vehicles. One such problem relates to the fact that once the curtain has been rolled or folded into a tubular-shaped bundle, portions of the curtain tend to twist, kink, or become otherwise entangled. Twisting is particularly troublesome between the textile cushion/metal gas guide junction and the nearest mounting location to the roof rail. The twisting of the inflatable curtain at this critical junction is detrimental because if a vehicle manufacturer installs the curtain in this twisted shape or the curtain is twisted during service, there is an increased likelihood that the curtain will fail, rip, deploy improperly, and/or otherwise malfunction during an accident. Vehicle occupants are endangered thereby.
In an attempt to reduce the likelihood that the inflatable curtain will be installed with a twisted shape, some recent inflatable curtains have been made with alignment lines or other similar markings that give a visual indication to the airbag installer or servicer if the curtain has been assembled having a twist or other entanglement. Unfortunately however, many vehicle manufacturers do not favor the use of these alignment lines because they believe that a visual inspection of the alignment lines does not provide a reliable and repeatable mechanism for determining whether the installed curtain contains a twist.
Moreover, vehicle manufacturers further do not favor the use of alignment lines because the alignment lines can significantly increase the total costs associated with producing, assembling, and installing the inflatable airbag curtain system. For example, requiring airbag installers or servicers to visually inspect the alignment lines after the curtain has been installed into the vehicles means that the overall time needed to install the curtain must be increased. As manufacturers incur costs for every moment that passes during the assembly process, even an increase of a few seconds or minutes in the assembly time represents a significant impact on the manufacturer's total production costs and overall profit margin of a mass-produced vehicle.
Accordingly, a need exists for an inflatable airbag curtain assembly that is difficult to twist, particularly during production, installation, or service of the inflatable curtain. It is particularly desirable that twisting of the curtain be prevented adjacent the junction of the textile inlet port of the curtain and the gas guide to the inflator. It is also desirable to prevent twisting of the curtain along its longitudinal length. It is further desirable that an inflatable curtain assembly be installable without relying solely on the efforts of the installers to align the curtain properly without kinks, crimps or twists. It is also desirable for an inflatable curtain assembly to be installable in a way that proper orientation of the gas guide and the inflatable curtain is achieved. Such a device is disclosed herein.